Do Voters Care about Incumbency?

Do Voters Care about Incumbency? Adam R. Brown Dept of Political Science Brigham Young University Last update: August 1, 2012 This is still a work in progress, so please check with me before citing. Comments welcome: brown@byu.edu http://adambrown.info/

Abstract We have long known that US House incumbents enjoy profound electoral advantages. However, existing research has not asked whether individual voters actually prefer incumbents over newcomers, other things being equal. Instead, existing research has focused on showing that other things aren t equal, by emphasizing the structural advantages that incumbents enjoy. I present experimental evidence showing that voters prefer incumbents even when the structural advantages are held constant. I supplement this experimental evidence with observational data showing that the incumbency advantage is greater in California, where incumbency status appears on the ballot, than in Florida, where it does not appear on the ballot.

1 Prior to the 2010 Congressional elections, the New York Times, the Washington Post, and countless other media outlets warned of a powerful anti-incumbent mood, one with the potential to send unprecedented numbers of Representatives packing. 1 In the end, however, 86% of U.S. House incumbents who sought reelection won. 2 While this reelection rate was slightly lower than has been typical in recent years, it was much higher than we might expect if voters really were in an anti-incumbent mood. Existing political science research gives us little reason to be surprised by this high reelection rate. Indeed, the research literature shows abundantly that incumbency confers profound electoral advantages. In explaining the origins of this advantage, existing research has generally focused on the structural advantages of incumbency. That is, existing research has shown how incumbents can use the perks of office to build up their name recognition, deter strong challengers, and ultimately win more votes. However, these structural explanations do not tell us whether individual voters actually like incumbents, other things being equal. Instead, these structural explanations merely stress that other things are not equal. Several political scientists have speculated over the years in their published work that voters might actually prefer incumbents over challengers, but none have tested these speculations empirically. It is past time to assess what voters actually think about incumbency. This question has both theoretical and practical relevance. Foremost among its practical implications stands the sticky matter of ballot design. Some states indicate on their printed 1 See [Gallup] Polls Reflect Anti-Incumbent Mood, from the Caucus at The New York Times, posted June 8, 2010 at <http://thecaucus.blogs.nytimes.com/2010/06/08/polls-reflect-anti-incumbent-mood/>; Voters Support for Members of Congress is at an All-Time Low, [Washington Post-ABC News] Poll Finds June 8, 2010, Washington Post. 2 Of 398 incumbents who sought reelection, 4 lost in primaries and 53 lost in November, an 85.7% reelection rate. Of the 37 retirements, 18 left to run for another office (usually Senate) and 3 retired due to failing health, leaving 16 retirements that may have been strategic decisions to avoid a certain defeat. Even if we count these 16 retirements as defeated incumbents, however, the reelection rate is still a respectable 341 out of 414, or 82.4%.

2 ballots which candidate is the incumbent; others do not. If voters have preferences about incumbency (other things being equal), then these seemingly-innocuous ballot design decisions could have meaningful impacts on election day. In the following pages, I present the results of a randomized experiment that directly tests whether voters have preferences about incumbency. I find evidence that voters actually prefer incumbents over challengers, even when the structural advantages are held constant. I supplement these experimental results with observational data suggesting that the incumbency advantage is larger in states that include incumbency information on the ballot than in states that omit this information. The Structural Incumbency Advantage There is no question that Congressional incumbents enjoy profound electoral advantages. Only twice since 1976 have fewer than 90 percent of House incumbents who sought reelection won it. 3 Most incumbents win by large margins. Researchers seeking to explain these trends have generally pointed to structural factors, which can be grouped into three broad categories. First, incumbents can use the resources of office to promote their brand and enhance their name recognition. Mayhew (1974) famously argued that Congress is perfectly structured to enable credit claiming (such as slipping district-based pork into legislation), position taking (staking out a popular stance on an issue without having to specify details), and advertising (sending out franked mailings and taking other actions to enhance name recognition). Using similar logic, Fiorina (1977) argued that incumbents can do favors for their constituents casework to build non-partisan favorability among constituents. In their quest to promote 3 The years were 1992 and 2010. For additional background data of this sort, refer to Jacobson (2013, 29-46).

3 themselves, incumbents also exploit the informal resources of office, such as opportunities to make speeches in the district throughout the year. Even such trivial perks of office as invitations to appear on The Colbert Report can benefit incumbents (Fowler 2008). At a minimum, these formal and informal resources help incumbents build up name recognition within their districts, and name recognition has been shown to help incumbents on election day (Box-Steffensmeier, Jacobson, and Grant 2000). More broadly, these resources may enable incumbents to cultivate an apolitical appeal, one that enables individual incumbents to remain personally popular within their respective districts even if Congress itself is deeply unpopular (Fenno 1975; Parker and Davidson 1979). Second, incumbents have existing support networks waiting to be tapped when a challenge arises. Incumbents tend to mentally divide their constituency into their weakest and strongest supporters, and then labor vigorously to expand their personal following (Fenno 1978), eventually resulting in a personal vote (Ansolabehere, Snyder, and Stewart 2000). When a tough challenge comes along, an incumbent can pull out donor lists, volunteer lists, and mailing lists from previous campaigns to rapidly mobilize her supporters. By contrast, a challenger would need to invest considerable time and energy into identifying and building a relationship with his core constituencies. Because incumbents already have existing support networks, they can generally raise money far more easily than challengers can. 4 Third, a challenger scare-off effect enhances any other structural advantages of incumbency (Cox and Katz 1996). Potential challengers are strategic. The more a potential 4 There has been considerable debate concerning the effects of incumbent and challenger spending on Congressional election results. Several models show that incumbent spending actually hurts the incumbent s vote share, since incumbents tend to spend only when threatened, whereas challenger spending helps the challenger s vote share (Jacobson 1980, 136-145; Jacobson 1985; Jacobson 1990). Competing models suggest that incumbent spending does have powerful effects, especially Green and Krasno s work (1988, 1990).

4 challenger has to lose by running for office, the less likely he is to run and the most experienced potential candidates often have the most to lose (Jacobson and Kernell 1983). Consider, for example, the plight of state legislators. Because most states hold their legislative elections concurrently with federal elections, state legislators would typically need to retire from their current office to run for the U.S. House. A state legislator who runs for Congress but loses will find himself out of political office, perhaps permanently. Thus, state legislators who arguably have the best shot at matching a U.S. Representative s political skill and resources also have the most to lose from running. Many Congressional races are foregone before the campaign even gets underway merely because the strongest challengers decline to run an uphill battle against an entrenched incumbent (Stone, Maisel, and Maestas 2004). We see, then, that the literature s explanations of the incumbency advantage rely heavily on structural logic. The first set of theories emphasizes the resources of office that incumbents enjoy; the second emphasizes the existing support networks that incumbents can tap into; and the third emphasizes the challenger deterrence effect. Most published explanations of the incumbency advantage can be classified into one or more of these categories. Observe that none of these structural approaches implies that individual voters like or dislike incumbents. Instead, these structural theories imply that incumbents can win reelection whether voters like incumbency or not (Parker and Davidson 1979). Indeed, these structural theories may explain why so many incumbents win reelection each year even though voters routinely tell pollsters that they are dissatisfied with Congress. In June 2010, only 32% of voters felt that most members of Congress deserved reelection; even among Democratic respondents,

5 whose party controlled Congress, only 53% felt that most members deserved reelection. 5 The fact that 85.7% of incumbents won anyway suggests that these structural theories have something right. Incumbents, it seems, can win even if voters are unhappy with Congress as a whole. Do Voters Care about Incumbency? As insightful as existing research has been, though, it has not asked what voters think about incumbents qua incumbents. Voters rarely have enough information to behave the way democratic theorists might like, but they compensate by relying heavily on information shortcuts (see, e.g., Lupia and McCubbins 1998). Given that partisanship and incumbency are often the only two shortcuts available on the ballot itself, we might reasonably expect voters to make use of both of them. This possible incumbency shortcut has been mentioned on occasion in published political science research, usually with the assumption that voters would respond positively to incumbency status. As early as 1957, Campbell and Miller suggested that voters might choose candidates merely because of their designation as incumbents on the ballot (Campbell and Miller 1957, 305). In the midst of the Southern realignment, Ferejohn (1977) and Cover (1977) supposed that declining party loyalty might make incumbency an even more important voting cue. To the extent that the declining partisanship of the 1970s and 1980s rendered partisan shortcuts less useful, they suggested, we might expect the incumbency shortcut to become more useful. Ansolabehere, Snyder, and Stewart (2000) echoed this logic, writing that incumbency may simply act as a voting cue, a label which voters rely on because party has become less 5 See <http://www.gallup.com/poll/139409/voters-favor-congressional-newcomers-incumbents.aspx>, accessed November 10, 2010.

6 relevant. All these authors supposed that voters who knew nothing about a particular race might prefer the incumbent over the challenger, other things being equal, although none of them tested these conjectures fully. To be clear, I do not mean that nobody has tested whether voters seem to vote for incumbents more often than they vote for challengers; political scientists have spilled barrels of ink showing that voters are far more likely to support incumbents than challengers, especially in House elections. 6 Rather, I mean that nobody has tested whether voters react to the simple fact of incumbency, once all the structural advantages of incumbency are held constant. To conduct that sort of test, with the structural advantages of incumbency held constant, requires controlled experimentation. Observational studies based on election results or public opinion polls can demonstrate that voters are drawn toward incumbents, but observational studies cannot disentangle the structural advantages of incumbency from voters raw feelings about incumbency itself. Before presenting my experiments, however, it is worth considering research from other fields that lends support to the conjectures noted above. After all, it may come as a surprise to some readers that so many political scientists have supposed that voters would be attracted toward incumbency rather than repulsed by it. Research in other fields lends theoretical support to these conjectures about incumbency. For example, economists have uncovered evidence of a status quo bias in decision making: People will only switch to a new policy if they strictly prefer it to the old one (Fatas, Neugebauer, and Tamborero 2007; emphasis added). Faced with a choice between preserving the status quo and switching to an unknown alternative, experiments 6 Among the earliest studies of this sort were Abramowitz (1975), Ferejohn (1977), and Nelson (1978). Good overviews are in Jacobson (2013) and Herrnson (2008).

7 suggest that people will choose the status quo. Applying similar logic, Samuelson and Zeckhauser extrapolated from their (non-political) experimental results to predict that status quo bias could lead voters to elect an incumbent to still another term in office (1988, 8); specifically, they calculated that status quo bias alone could shift what might otherwise be a perfectly divided 50-50 vote into a 59-41 vote sending an incumbent back to Washington (1988, 9). Whatever the precise causal mechanism may be, an individual-level preference for incumbents over challengers has been conjectured frequently enough in the research literature to warrant testing whether it actually exists. Hypothesis 1: Other things being equal, voters prefer incumbents over challengers. Of course, incumbency might just as easily evoke a negative response from voters. The same emotions that motivate voters to support term limits might also motivate them to oppose incumbents as a general rule. Political scientists have not had much to say about this possibility. To be sure, previous research has shown that voters frequently have harsh evaluations of Congress as a whole, but these observations are usually followed by an argument that the structural advantages of incumbency enable Representatives to continue winning reelection despite these negative feelings about the institution as a whole. Fenno (1975) said it best: If our congressmen are so good, how can our Congress be so bad? We apply different standards of judgment, those that we apply to the individual being less demanding than those we apply to the institution (see also Hibbing and Theiss-Morse 1995). Although political scientists have not said much about incumbency as a liability,

8 however, several political commentators promoted this sort of reasoning prior to the 2010 elections: Undecideds usually break against the incumbent, wrote one, without providing supporting evidence. 7 Press coverage and punditry generally framed coverage of the 2010 Congressional elections around a supposed anti-incumbent mood, as noted above. Suggestions that incumbency might be a liability tended to focus especially on those who had served for many, many years. For example, after Senator Bob Bennett surprisingly lost his party s renomination, political commentators were quick to suppose that during his 18 years in office he had simply lost touch with voters. This logic suggests the opposite hypothesis to that given above namely, that voters prefer challengers over incumbents, especially in the case of longterm incumbents. Hypothesis 2: Other things being equal, voters prefer challengers over incumbents especially when the incumbent has served for a long time. Of course, it s possible that voters react to incumbency differently depending on their partisanship. As noted earlier, Gallup reported in June 2010 that only 32% of voters felt that most members of Congress deserved reelection. Among Republicans, the number fell to 16%; among Democrats, it rose to 53%. This partisan pattern is hardly surprising given that Democrats controlled Congress. This pattern implies that voters were mentally changing the question from asking about most members to asking about most majority (Democratic) members. If so, then perhaps incumbency is useful as a shortcut only to the extent that it helps voters infer a candidate s partisanship. If each candidate s partisanship were already known, we might expect incumbency to have far less influence as a voting cue. Surely Gallup would have found different 7 The quote is from Sean Trende at Real Clear Politics (see http://www.realclearpolitics.com/articles/2010/10/07/the_democrats_dead_cat_bounce_107476.html). See also Michael Barone at The Washington Examiner (http://www.washingtonexaminer.com/politics/house-democratshead-for-a-thumping-at-the-polls-1004124-99388554.html).

9 results if it had asked separately whether most Republican members and most Democratic members deserve reelection. On real ballots, unlike in Gallup s poll, voters can usually see each candidate s partisan affiliation. We can easily test whether stating partisan affiliations alongside incumbency status negates the sort of partisan pattern apparent in Gallup s results: Hypothesis 3: Any effects of incumbency status on voter behavior will diminish or disappear when each candidate s partisanship is known. Experimental Conditions I present below the results of a few simple survey experiments that test these hypotheses directly. An initial wave of 979 respondents was recruited from July 16-29, 2012, using Amazon s Mechanical Turk service (hereafter MTurk ) 8 ; a second wave will participate in November 2012 as part of the Cooperative Congressional Election Study (hereafter CCES ). 9 All respondents were presented with brief profiles of two fictional Congressional candidates, Steven Redden and Ray Kepler. The candidates were characterized as actual candidates running against each other in another state. After reading the profiles, respondents indicated their preferred candidate along a 7-point scale, where 1 indicates strong support for Redden and 7 indicates strong support for Kepler. 10 Table 1 presents the actual question wording and formatting. [Table 1 about here] 8 Only MTurk users from the United States were included. Each participant received $0.21 in compensation. Although MTurk users are a convenience sample, Berinsky et al. (2012) performed several classic political science experiments on both MTurk respondents and on representative samples and found that both populations produced similar results. 9 Demographic statistics for both waves are found in the appendix s Table A1. 10 Respondents did not see the numbers; the scale was presented as a Likert scale with a candidate s name anchoring each end.

10 The candidate profiles were varied along two dimensions. 11 First, references to candidate partisanship varied. One-third of respondents saw the partisan descriptions shown in Table 1; one-third saw the partisanship reversed; and one-third saw no reference to partisanship at all. Second, references to incumbency varied. Some respondents saw a brief paragraph inserted into the middle of Ray Kepler s profile characterizing him as an incumbent. This language took a few different forms, as shown in Table 2. One-third of respondents saw no reference to incumbency; one-third saw the Incumbency: No length treatment; and one-third of respondents saw either the 2 years or 22 years treatment. [Table 2 about here] Respondents were randomly assigned into the three partisan conditions and the four incumbency conditions. It appears the randomization worked ; assignment to these conditions does not correlate meaningfully with respondent age, partisanship, education, or gender. Because respondents were randomly assigned into the experimental conditions, it is unnecessary to include any demographic control variables in the analysis that follows. The difficulty with vignette experiments like these is that the treatment language can be so subtle that respondents fail to notice it (Mutz 2011, 84). The MTurk wave employed manipulation checks to guard against this possibility. After indicating their preferred candidate, respondents were shown a new screen asking three factual questions about the candidates. The first question asked which candidate had spent more money on the race; the second asked which candidate was the incumbent; and the third asked which candidate was the Republican. Overall, 89% of respondents answered at least two of the three questions correctly, and 63% answered all 11 For MTurk users, but not for CCES respondents, profiles varied along a third dimension: The order of the candidate profiles. In analyzing the MTurk data, I found that it made no difference which profile appeared at left, so this dimension was omitted from the CCES experiment.

11 three correctly. Accuracy rates were high across all experimental conditions, 12 even though respondents generally completed the survey very quickly. 13 It appears that the experimental manipulations effectively attracted respondents notice. Findings In analyzing the experimental data, the dependent variable is the respondent s preferred candidate. This variable is coded on a seven-point scale where 1 indicates firm support for Redden while a 7 indicates firm support for Kepler. I estimate the effects of the various experimental conditions on this 7-point scale using ordinary least squares regressions. The incumbency treatments described above were applied only to Kepler. Thus, a positive coefficient on one of the dummy variables designating an incumbency treatment condition indicates that respondents reacted favorably to incumbency status. Table 3 shows the estimated effect of incumbency status on vote choice. Candidate partisanship enters the models via the trichotomous party effect variable. This variable is coded +1 for respondents whose partisanship aligns with Kepler s, which would lead to a higher expected score on the dependent variable, and -1 for respondents whose partisanship aligns with Redden s, which would have the opposite effect. This variable is coded as 0 for respondents who are pure independents; the handful of respondents who indicated a preference for a minor party are omitted. It is also coded 0 for respondents who were not shown party labels. Separately, the 12 For incumbency, 89% correctly chose I don t know in the incumbency control condition, and 73% correctly chose Kepler in the treatment conditions. For partisanship, 76% correctly chose I don t know in the partisanship control condition, and 88% correctly identified the Republican candidate when partisanship was explicitly mentioned. 13 The survey involved a consent screen, the treatment question, the three manipulation check questions, and four demographic questions, with each portion displayed on a separate screen. Still, the median respondent spent only 75 seconds on the survey, with the 25 th and 75 th percentiles at 60 and 94 seconds, respectively. Even among those who spent 42 seconds or less on the survey (the 5 th percentile), 64% answered at least two of the manipulation checks correctly.

12 party labels present variable is coded 1 for respondents who were shown each candidate s partisanship and 0 otherwise. [Table 3 about here] In Model 1a, all three incumbency treatments are pooled into a single dummy variable, with respondents who saw no reference to incumbency as the omitted category. Other things being equal, those who saw Kepler characterized as an incumbent became more favorable toward him. At first blush, the estimated coefficient of 0.19 in Model 1a may seem extremely small; after all, the vote choice variable used a 7-point scale. Looking at the data from another angle, however, suggests that the practical effects of even this small coefficient could be large on election day. Suppose that we treated respondents choosing 1, 2, or 3 on the 7-point vote choice scale as sure votes for Redden, and respondents choosing 5, 6, or 7 as sure votes for Kepler. 14 Using this procedure, we find that only 47.7% of respondents in the control condition voted for Kepler, while 55.5% in the treatment condition did so. 15 This 7.8 percentage point shift is stunningly similar to the 9 percentage point shift predicted by Samuelson and Zeckhauser (1988), discussed above. Other things being equal, it appears that voters are drawn to incumbents, not repulsed by them. Model 1b disaggregates the three incumbency treatments. Perhaps as an outgrowth of the decreased sample size within each condition, the three treatment dummies vary in their statistical significance. Still, all three coefficients remain positive, and none of them is statistically different 14 This produces a dichotomous dependent variable that can be modeled using probit. The results appear in the appendix s Table A2. The probit models suggest similar conclusions as those reported here, with estimated coefficients on the incumbency variables that are more consistently statistically significant than those reported here. 15 I ignore respondents who chose 4 on the vote choice scale. If, instead, these respondents are assumed to choose randomly between the two candidates, with half going each way, then Kepler s vote rises from 48.2% in the control to 54.4% in the treatment.

13 from the others. Perhaps most striking of all, voters do not seem to care at all whether an incumbent has served for 2 years or for 22; the estimated treatment effect in both conditions is almost identical. Taken together, Models 1a and 1b provide evidence in favor of Hypothesis 1 (voters are drawn toward incumbents) and against Hypothesis 2 (voters are repulsed by incumbents). Hypothesis 3 (the effects of incumbency diminish when candidate partisanship is known) remains to be tested. To test Hypothesis 3, Models 2a and 2b insert an interaction between the treatment dummies and the party labels present dummy. Hypothesis 3 would predict negative interactions in every case. As it happens, all the interactions are indeed negative, but none comes close to attaining statistical significance. If there is an interaction, the effect is too small to identify here. Elections in California and Florida Randomized experiments can produce interesting results, but there is always a lingering question whether the results carry into the real world. As evidence that these experimental findings do reflect phenomena that arise in real elections, consider a brief comparison of U.S. House elections held in California and Florida. Ballots in California indicate which candidate is the incumbent; ballots in Florida do not. Both states are home to large, diverse populations, with large Congressional delegations, creating an ideal setting for a statistical comparison. Gelman and King (1990) introduced a simple, unbiased way to calculate incumbency advantage: Regress the Democrat s share of the two-party vote on the lagged vote, a dummy

14 indicating which party currently holds the seat, and a trichotomous incumbency dummy coded -1 for a Republican incumbent, +1 for a Democratic incumbent, and 0 for an open seat. I also include a dummy for each separate year, with 2004 as the baseline. 16 I collected data on all U.S. House races held in Florida and California from 2002 through 2010. Like Gelman and King, I omit uncontested seats (including seats that were uncontested in the lag). Applying the Gelman-King method to these Congressional races produces the models shown in Table 4. Model 4a shows that incumbents in California and Florida enjoyed a 4.75 percentage point advantage from 2004 through 2010. Model 4b adds a twist, however, by interacting the trichotomous incumbency indicator with the California dummy. We see that the incumbency advantage was significantly larger in California than in Florida. In Florida, incumbents enjoyed a 3.12 percentage point advantage. In California, the advantage was nearly double, with incumbents enjoying a 6.18 percentage point advantage. U.S. House incumbents enjoy the same structural advantages whether they come from California or Florida. Incumbents in both states have existing support networks, incumbents in both states have access to the resources of office, and incumbents in both states should be able to deter challengers. They do differ, however, in terms of the information presented to voters on the ballot. Although many voters would recognize the incumbent s name even if incumbency status were not printed on the ballot (see Jacobson 2013, 132-133), printing it there increases the incumbent s vote share by more than three percentage points. 16 Gelman and King ran their model separately for each year to estimate annual changes in the incumbency advantage. Since I am studying only two states, I pool all years from 2004 through 2010 to ensure adequate sample size. This pooling makes it necessary to insert a dummy for each election year under consideration.

15 Conclusion Existing explanations of the incumbency advantage have focused entirely on the structural advantages of incumbency such as the resources of office, existing support networks, and challenger deterrence. Rather than ask whether voters prefer incumbents over challengers, other things being equal, existing research has labored (successfully) to demonstrate that other things are not equal. Still, political scientists and pundits have frequently speculated as to how voters might react to incumbency status in the absence of these structural advantages. The experiments described here are the first (to my knowledge) to address that question empirically. The randomized experimentation employed here holds the structural perks of incumbency constant. The estimated coefficients are not large, but these experiments do provide evidence that respondents prefer incumbents over challengers, other things being equal. The results reported above suggest that incumbency status alone holding all the structural advantages constant can add 7-8 percentage points to an incumbent s vote total. To put this finding in context, consider that the incumbency advantage added between 5 and 8 percentage points to House incumbents vote totals in the 2004, 2006, 2008, and 2010 Congressional elections. 17 In other words, the effects of incumbency status estimated here are large enough to explain the entire observed incumbency advantage. Although the structural advantages are certainly important, as evidenced by the many rigorous studies cited earlier, future work should consider more carefully why individual voters might prefer incumbents over challengers even in the absence of these structural advantages. 17 Calculated by Jacobson (2013, 34) using the Gelman-King (1990) method.

16 References Abramowitz, Alan I. 1974. Name familiarity, reputation, and the incumbency effect in a Congressional election. Western Political Quarterly 28 (December): 668-684. Ansolabehere, Stephen, James M. Snyder Jr., and Charles Stewart III. 2000. Old voters, new voters, and the personal vote: Using redistricting to measure the incumbency advantage. American Journal of Political Science 44 (January): 17-34. Berinsky, Adam J., Gregory A. Huber, and Gabriel S. Lenz. 2012. Evaluating online labor markets for experimental research: Amazon.com s Mechanical Turk. Political Analysis. Box-Steffensmeier, Janet M., Gary C. Jacobson, and J. Tobin Grant. 2000. Question wording and the House vote choice: Some experimental evidence. Public Opinion Quarterly 64 (autumn): 257-270. Campbell, Angus, and Warren E. Miller. 1957. The motivational basis of straight and split ticket voting. American Political Science Review 51 (June): 293-312. Cover, Albert D. 1977. One good term deserves another: The advantage of incumbency in Congressional elections. American Journal of Political Science 21 (September): 523-541. Cox, Gary W., and Jonathan N. Katz. 1996. Why did the incumbency advantage in U.S. House elections grow? American Journal of Political Science 40 (May): 478-497. Fatas, Enrique, Tibor Neugebauer, and Pilar Tamborero. 2007. How politicians make decisions: A political choice experiment. Journal of Economics 92 (2): 167-196. Fenno, Richard F., Jr. 1975. If, as Ralph Nader says, Congress if the broken branch, how come we love our Congressmen so much? In Congress in Change: Evolution and Reform, ed. Norman J. Ornstein. New York: Praeger. Fenno, Richard F., Jr. 1978. Home style: House members in their districts. Boston: Little, Brown. Ferejohn, John A. 1977. On the decline of competition in Congressional elections. American Political Science Review 71 (March): 166-176 Fiorina, Morris P. 1977. The case of the vanishing marginals: The bureaucracy did it. American Political Science Review 71 (March): 177-181. Fowler, James H. 2008. The Colbert bump in campaign donations: More truthful than truthy. PS: Political Science and Politics 41 (3): 533-539. Gelman, Andrew, and Gary King. 1990. Estimating incumbency advantage without bias. American Journal of Political Science 34 (November): 1142-1164. Green, Donald Philip, and Jonathan S. Krasno. 1988. Salvation for the spendthrift incumbent: Reestimating the effects of campaign spending in House elections. American Journal of Political Science 32 (November): 884-907.

17 Green, Donald Philip, and Jonathan S. Krasno. 1990. Rebuttal to Jacobson s New Evidence for Old Arguments. American Journal of Political Science 34 (May): 363-372. Herrnson, Paul S. 2008. Congressional elections: Campaigning at home and in Washington. Washington DC: CQ Press. Hibbing, John R., and Elizabetah Theiss-Morse. 1995. Congress as public enemy: Public attitudes toward American political institutions. Cambridge: Cambridge University Press. Jacobson, Gary C. 1980. Money in Congressional elections. New Haven: Yale University Press. Jacobson, Gary C. 1985. Money and votes reconsidered: Congressional elections. Public Choice 47 (January): 7-62. Jacobson, Gary C. 1990. The effects of campaign spending in House elections: New evidence for old arguments. American Journal of Political Science 34 (May): 334-362. Jacobson, Gary C. 2013. The politics of Congressional elections, 8 th Education. ed. Boston: Pearson Jacobson, Gary C., and Samuel Kernell. 1983. Strategy and choice in Congressional elections. New Haven: Yale University Press. Lupia, Arthur, and Mathew D. McCubbins. 1998. The democratic dilemma: Can citizens learn what they need to know? Cambridge: Cambridge University Press. Mayhew, David R. 1974. Congress: The Electoral Connection. New Haven: Yale University Press. Mutz, Diana C. 2011. Population-based survey experiments. Princeton: Princeton University Press. Nelson, Candice J. 1978. The effect of incumbency on voting in Congressional elections, 1964-1974. Political Science Quarterly 4 (winter): 665-678. Parker, Glenn R., and Roger H. Davidson. 1979. Why do Americans love their Congressmen so much more than their Congress? Legislative Studies Quarterly 4 (February): 53-61. Samuelson, William, and Richard Zeckhauser. 1988. Status quo bias in decision making. Journal of Risk and Uncertainty 1: 7-59. Stone, Walter J., Sandy L. Maisel, and Cherie D. Maestas. 2004. Quality counts: Extending the strategic politician model of incumbent deterrence. American Journal of Political Science 48 (July): 479 495.

Table 1: Question Wording 18

19 Table 2: Treatment Language for Incumbency Status Group Control Incumbency: No length Incumbency: 2 years Incumbency: 22 years Language (No mention of incumbency) Kepler is the current Representative. He is seeking reelection to another term. Kepler has served in Congress for the past 2 years. He is seeking reelection to another term. Kepler has served in Congress for the past 22 years. He is seeking reelection to another term.

20 Table 3: Effects of Incumbency on Vote Choice (MTurk Respondents) Model 1a Model 1b Model 2a Model 2b Incumbency (any type) 0.19* -- 0.28 -- (0.09) (0.16) party labels present -- -- -0.14 -- (0.19) Incumbency: No length -- 0.11 (0.10) -- 0.16 (0.18) party labels present -- -- -- -0.068 (0.22) Incumbency: 2 years -- 0.30* (0.14) -- 0.32 (0.24) party labels present -- -- -- -0.026 (0.29) Incumbency: 22 years -- 0.26+ (0.13) -- 0.53* (0.23) party labels present -- -- -- -0.41 (0.28) Party effect 1.43** (0.059) 1.42** (0.059) 1.43** (0.059) 1.42** (0.059) Party labels present 0.041 (0.092) 0.040 (0.092) 0.13 (0.16) 0.13 (0.16) Constant 3.96** (0.095) 3.96** (0.095) 3.90** (0.13) 3.90** (0.13) N 958 958 958 958 R 2 (adj.) 0.38 (0.38) 0.38 (0.38) 0.38 (0.38) 0.38 (0.38) p 0.10, *p 0.05, **p 0.01 (one-tailed). The dependent variable is a 7-point vote choice indicator.

21 Table 4: Incumbency Advantage in Florida and California Model 4a Model 4b Lagged Democratic vote 0.77** (0.051) 0.74** (0.052) Seat currently held by Democrats? -3.63 (3.75) -4.30 (3.71) Incumbency indicator 4.75** (1.73) 3.12 (1.81) California dummy -- 3.05** (1.12) California dummy 2.81** (0.97) 4.22** (1.08) Year 2006 dummy 2.25* (1.12) 2.18* (1.10) Year 2008 dummy 1.76 (1.11) 1.89 (1.10) Year 2010 dummy -5.88** (1.10) -5.33** (1.11) Constant 12.54** (2.54) 12.91** (2.51) N 236 236 R 2 (adj.) 0.90 (0.90) 0.90 (0.90) p 0.10, *p 0.05, **p 0.01 (one-tailed). The dependent variable is the Democratic candidate s share of the two-party vote.

Appendix 22

23 Table A1: Profile of Respondents MTurk Number of respondents 979 Gender Male 62.1% Female 37.9% Age 25 th percentile 22 50 th percentile 25 75 th percentile 32 Average age 28.4 Partisanship Strong Democrat 10.3% Democrat 23.4% Independent, leaning Democrat 24.2% Independent 18.8% Independent, leaning Republican 12.0% Republican 6.8% Strong Republican 1.4% Another party 3.1% Education Less than high school 0.5% High school diploma 10.6% Some college 45.9% Four-year college degree 34.3% Graduate degree 8.7% CCES

24 Table A2: Effects of Incumbency on Dichotomous Vote Choice (MTurk Respondents) Model 1a Model 1b Model 2a Model 2b Incumbency (any type) 0.30* -- 0.37* -- (0.12) (0.18) party labels present -- -- -0.12 -- (0.24) Incumbency: No length -- 0.28* (0.13) -- 0.24 (0.20) party labels present -- -- -- 0.07 (0.27) Incumbency: 2 years -- 0.37* (0.17) -- 0.51 (0.28) party labels present -- -- -- -0.22 (0.36) Incumbency: 22 years -- 0.29 (0.17) -- 0.58* (0.26) party labels present -- -- -- -0.52 (0.35) Party effect 1.45** (0.091) 1.45** (0.091) 1.45** (0.091) 1.45** (0.092) Party labels present 0.16 (0.11) 0.15 (0.11) 0.23 (0.19) 0.24 (0.19) Constant -0.15 (0.11) -0.15 (0.11) -0.20 (0.14) -0.20 (0.14) N 755 755 755 755 p 0.10, *p 0.05, **p 0.01 (one-tailed). The dependent variable is a dichotomous vote choice indicator derived from the 7-point vote choice indicator using the procedure described in the main text.